Premium
Melatonin regulates the respiratory burst of human neutrophils and their depolarization
Author(s) -
Pieri Carlo,
Recchioni Rina,
Moroni Fausto,
Marcheselli Fiorella,
Marra Maurizio,
Marii Silvia,
Primio Roberto
Publication year - 1998
Publication title -
journal of pineal research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.881
H-Index - 131
eISSN - 1600-079X
pISSN - 0742-3098
DOI - 10.1111/j.1600-079x.1998.tb00364.x
Subject(s) - depolarization , melatonin , respiratory burst , rhodamine 123 , membrane potential , stimulation , intracellular , biophysics , extracellular , chemistry , biology , phorbol , medicine , endocrinology , biochemistry , protein kinase c , signal transduction , multiple drug resistance , antibiotics
Pieri C, Recchioni R, Moroni F, Marcheselli F, Marra M, Marinoni Silvia, Di Primio R. Melatonin regulates the respiratory burst of human neutrophils and their depolarization. J. Pineal Res. 1998; 24:43–49. © Munksgaard, Copenhagen Abstract The effect of different doses of melatonin on the respiratory burst as well as on the membrane potential changes of human neutrophils stimulated with phorbol 12‐myristate 13‐acetate (PMA) was investigated. The intracellular production of reactive oxygen species (ROS) in stimulated neutrophils was quantified in individual cells by flow cytometry, measuring the oxidation of nonfluorescent dihydrorhodamine 123 to the green fluorescent rhodamine 123. The transmembrane potential change was measured using the fluorescent probe oxonol. Preincubating the cells with micromolar concentrations of the indole resulted in an increase of the response to PMA. In two of six subjects investigated, the respiratory burst was also increased by a 10 nM concentration of the indole, but when the melatonin concentration was increased to 2 mM the respiratory burst was inhibited. The change in the transmembrane potential of neutrophils paralleled the respiratory burst. Indeed, the treatment of the cells with doses of melatonin up to 0.5 mM increased the depolarization occurring subsequent to PMA stimulation, whereas 2 mM melatonin concentration decreased the extent of depolarization. To investigate whether melatonin could directly affect the transmembrane potential changes of neutrophils, the extent of depolarization, induced by increasing the extracellular potassium concentration, was measured in cells preincubated with 2 mM melatonin. This treatment resulted in a decrease of the extent of depolarization, which suggests that melatonin can directly alter membrane ion conductance in human neutrophils.